Living for God is not a matter of following a set of rules. God commanded the Israelites to follow a system of sacrifices, but Samuel said to Saul, "Has the LORD as great delight in burnt offerings and sacrifices, as in obeying the voice of the LORD? Behold, to obey is better than sacrifice, and to listen than the fat of rams" (1 Samuel 15:22). In order for us to live for God, we must know what He wants. Jesus, in His High Priestly prayer during His Upper Room Discourse (John 13—17), gives us insight into what He wants. He prayed, "I do not ask for these only, but also for those who will believe in me through their word, that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. The glory that you have given me I have given to them, that they may be one even as we are one, I in them and you in me, that they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me. Father, I desire that they also, whom you have given me, may be with me where I am, to see my glory that you have given me because you loved me before the foundation of the world. O righteous Father, even though the world does not know you, I know you, and these know that you have sent me. I made known to them your name, and I will continue to make it known, that the love with which you have loved me may be in them, and I in them" (John 17:20–26). He prays specifically for two things: 1) that all believers may be unified, and 2) that all believers will have an ongoing relationship with Him. Living for Him means that we want what He wants.
I want to live my life for God. How do I do that?
He also said, in John 14:15, "If you love me, you will keep my commandments." So in living for Him, we will keep His commandments. However, notice the order. We love Him and therefore keep His commandments. That we keep His commandments does not mean that we love Him. Our primary focus should be on what He wants: a relationship with Him and unity in the body. In order to do these things, we must continually pray and read and study His word. We must constantly ask the Holy Spirit to apply what we study to our lives and enable us to have the relationship with Jesus that He desires. And as we develop that relationship with Jesus, we will become unified with His people. And we will desire to obey His will more and more. We will want to know and keep His commandments.
In order to live for God, we must want what He wants. The rest will follow.
What is it to abide in Christ? What does it mean to abide in Christ?
What is meant by 'dying to self'? How are Christians supposed to die to self?
What is the key to knowing the will of God?
Who are we in Christ?
What does it mean for Christians to be in the world but not of the world?
Truth about the Christian Life